The present invention is directed to a system for sampling the air within an appliance shipping container and detecting the presence of contaminants in the air, and more particularly to a system for detecting a refrigerant leak from a refrigerator disposed within a shipping container.
Typically, an appliance such as an air conditioner, freezer or a refrigerator includes a refrigeration system having a compressor, evaporator and condenser sealably connected together and having a charge of pressurized refrigerant. More specifically, in the manufacture of refrigerator appliances, it is well known that leaks of refrigerant from the refrigeration system may cause the refrigerator to fail to operate. Further, the leaks in the refrigeration system may be of a very minute nature and accordingly are difficult to detect because the refrigerant used in most modern appliances is odorless and colorless.
Various methods are used therefore, for detecting leaks in the refrigeration system of the refrigerator during the manufacturing process of the refrigerator. For example, one such method includes submerging a portion of the refrigeration system, pressurized with compressed air, in a liquid bath and visually noting the presence of bubbles which indicate the presence of leaks. Another method involves pressurizing a portion or all of the refrigeration system using compressed air and monitoring the system for any loss of pressure which would indicate a leak.
Typically, the above mentioned leak detection methods are employed to identify leaks in the components of the refrigeration system and their interconnections prior to charging the system with refrigerant. However, leaks may develop in the refrigeration system after installation of the refrigeration system into the refrigerator cabinet structure and after the refrigeration system has been charged with refrigerant. These leaks may be due to damage which occurs during subsequent assembly and packaging steps of the refrigerator after the installation of the refrigeration system and handling of the refrigerator once it is in the shipping container.
It would be desirable, therefore, to develop a system for detecting leaks in a refrigeration system of a refrigerator upon the completion of the manufacturing process of the refrigerator. Such a system is made difficult by the fact that the typical refrigerant used in a refrigeration system is similar to the typical blowing agents used for providing foam insulation in the refrigerator. Therefore, leak detection equipment must be able to discriminate between refrigerant compounds and blowing agent compounds. Furthermore, a leak in the refrigeration system, which occurs after the system has been charged with refrigerant, will allow the refrigerant to leak from the system in a gaseous form and unless confined, the gaseous refrigerant will quickly disperse. A novel solution for detecting leaks in a refrigeration system may be found, however, by utilizing the shipping container surrounding the refrigerator as an enclosure for partially confining leaking refrigerant from the refrigeration system such that a novel method to detect leaks in a refrigeration system may operate by detecting the presence of the refrigerant as an air contaminant within the shipping container.